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831.
E. España P. Beneitez V. Soler T. Calderón 《Journal of Radioanalytical and Nuclear Chemistry》1993,173(1):55-66
A technique for quantitative analysis of different soils, ceramics, feldspars and natural halide samples is presented, based on the measurement of -activities using a Geiger-Müller system. The system was calibrated with KCl, KC8H5O4, KNO3 and K2SO4 standards and a potassium content of 1% yields a net -count rate (background subtracted) of about 55 cph. Precision values of less than ±0.4% K can be achieved in counting times of about 4 hours. The results agree with those obtained by means of other more common analytical methods such as flame photometry, atomic absorption and -spectrometry. In comparison with these methods, this approach is direct, precise and non-destructive, because the samples do not require prior treatment. 相似文献
832.
The paper describes magic labelings of type (1,1,1) for two classes of graphs, which are obtained by a combination of vertex, edge and face labelings. 相似文献
833.
Victor H. de la Peña 《Journal of Theoretical Probability》1993,6(2):285-302
In this paper we introduce a new tail probability version of Wald's lemma for expectations of randomly stopped sums of independent random variables. We also make a connection between the works of Klass(18, 19) and Gundy(11) on Wald's lemma. In making the connection, we develop new Lenglart and Good Lambda inequalities comparing the tails of various types of adapted processes. As a consequence of our Good Lambda inequalities we include the following result. Let {d i }, {e i } be two sequences of variables adapted to the same increasing sequence of σ-fields ? n ↗?, (e.g., ? n =σ({d i } i=1 n , {E i } i=1 n ), and letN?∞ be a stopping time adapted to {? n }. Then for allp>0, there exists a constant 0<C p <∞ depending onp only, such that $$\mathop {\overline {\lim } }\limits_\lambda \lambda ^p P\left( {\mathop {\sup }\limits_{1 \leqslant n \leqslant N} \left\| {\sum\limits_{i = 1}^n {d_i } } \right\| > \lambda } \right) \leqslant C_p \mathop {\overline {\lim } }\limits_\lambda \lambda ^p P\left( {\mathop {\sup }\limits_{1 \leqslant n \leqslant N} \left\| {\sum\limits_{i = 1}^n {e_i } } \right\| > \lambda } \right)$$ This result holds when the sequences are real, tangent, and either conditionally symmetric or nonnegative, or alternatively, if {d i } is a sequence of independent random variables and {e i } is an independent copy of {d i }, withN a stopping time adapted to the filtration generated by {d i } only. Other examples include Hilbert space valued differentially subordinate conditionally symmetric martingale differences. The result is true for more general operators applied to sequences as shown by an example comparing the square function of a conditionally symmetric sequence to the maximum of its absolute partial sums. 相似文献
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Rafael Bilbao María Benita Murillo Angela Millera Jos Francisco Mastral 《Thermochimica Acta》1991,190(2):163-173
An experimental system that allows the use of large particle sizes and the simulation of different operating conditions was built to study the thermal decomposition of lignocellulosic materials. The values of solid conversion and of temperature obtained at different points using spherical particles of pine wood 2 cm in diameter are shown. The conversion values are compared with those calculated from the equations obtained in a thermobalance for small particle sizes. 相似文献